Damage to plants caused by nematodes is a prevalent and serious economic problem. Nematodes cause wide-spread and serious damage in many plant species. Many genera of nematodes are known to cause such damage. Plant-parasitic nematodes include members of the Phylum Nematoda, Orders Tylenchida and Dorylaimide. In the Order Tylenchida, the plant-parasitic nematodes are found in two Super Families: Tylenchoidea and Criconematoidea. There are more than 100,000 described species of nematodes.
Nematicides routinely used for control of plant-parasitic nematodes are rapidly being pulled from the market as concern for environmental safety increases. In the year 2001, Methyl Bromide, a mainstay in the control of such parasites, will no longer be marketed in the United States. Therefore, less harmful control agents are clearly needed.
In addition, the regular use of chemical toms to control unwanted organisms can select for drug-resistant strains. This has occurred in many species of economically important insects and has also occurred in nematodes of sheep, goats, and horses. For example, an accepted methodology for control of nematodes has centered around the drug benzimidazole and its congeners. The use of these drugs on a wide scale has led to many instances of resistance among nematode populations (Prichard, R. K. et al. [1980] "The problem of anthelmintic resistance in nematodes," Austr. Vet. J. 56:239-251; Coles, G. C. [1986] "Anthelmintic resistance in sheep," In Veterinary Clinics of North America: Food Animal Practice, Vol 2:423-432 [Herd, R. P., eds.] W. B. Saunders, New York). The development of pesticide resistance necessitates a continuing search for new control agents having different modes of action.
As discussed in more detail below, nematodes sense the presence of and navigate toward root systems of plants. Our research has demonstrated that tannins are strong attractants of plant-parasitic nematodes. Certain aspects of the research described herein were presented at a science fair in February 1994.
Tannins are produced in the roots, stems, and leaves of almost all plants. It was known that tannins were present in the waste discharge of paper mills and nut-processing plants. See U.S. Pat. No. 3,855,121, Gough, Biochemical Process. Tannins are used, for example, to denature alcohol, to tan animal hides, as clarification agents in wine and beer manufacturing, in the production of inks, pharmaceuticals, and paper. Tannins can also be used to deodorize crude oil. Tannins are also used in the production of galvano-plastics (as a gelatin precipitant). Similarly, tannins have been used as complexing agents for gel matrices. See U.S. Pat. No. 4,779,376, Redenbaugh, Delivery System for Seeds; U.S. Pat. No. 4,583,320, Redenbaugh, Delivery System for Meristematic Tissue.